Food safety and labelling regulations are increasing with the volume of trade. This also represents a challenging situation for food supply chains. Industrial food processing further enhances the risks of contamination with microorganisms and inadvertent allergens. As consumers and regulatory bodies demand certainty in regard to the products, correct identification and labelling of ingredients is needed, for example, with respect to species in processed mixtures of meat or plant materials. This applies also to biological products such as garments, textiles and furs, e.g. many Western consumers do not wish to wear cat furs due to allergies or ethical reasons.
Isolation and PCR analysis of nucleic acids is a common method for detection and identification of species or undesired organisms. Commonly, the sample of biological material is disrupted mechanically and lysed by chemical treatment, followed by subsequent purification of the isolated nucleic acids. However, the raw and processed samples exhibit very diverse compositions and, accordingly, they require differential treatment and sample processing. It is difficult to know in advance which type of sample processing is needed to obtain enough and sufficiently pure nucleic acids for further PCR analysis.
EP 2 634 254 B1 (QIAGEN GmbH) discloses a method for isolating bacterial DNA from enrichment cultures, in which the sample is mixed with a water-immiscible substance. WO 2013/010674 A1 describes a DNA isolation method using a filtering device containing bentonite for a removal of proteins. The most established method for the isolation of genomic DNA employs the cationic surfactant hexadecyltrimethylammonium bromide (CTAB) for denaturing and removal of proteins (Drábková LZ et al., DNA extraction from herbarium specimens, Methods Mol Biol. 2014; 1115:69-84). This method requires the use of an expensive and hazardous chemical and is also laborious and time consuming. The state of the art represents, therefore, a problem.